Stabilized multi-wavelength laser system for non-invasive spectrophotometric monitoring

A spectroscopic system that monitors oxygenation levels in biological tissue, comprising:

• a sensor portion that includes a plurality of sensor assemblies, each sensor assembly having at least one light signal outlet, and at least one light detector adapted to sense light and produce detected signals;
• and
• a monitor portion having a processor in communication with each of the light detectors in each sensor assembly, a light source adapted to produce light signals at a plurality of different wavelengths, and an optical switch with two or more output ports and an input port, wherein each switch output port is adapted to be connected to the light signal outlet of a particular one of the sensor assemblies, and the switch input port is in communication with the light source;
• wherein the optical switch is adapted to selectively route light signals from the light source to each switch output port;
• and
• wherein the processor is adapted to process the detected signals to determine oxygenation levels within the biological tissue.

A method for spectrophotometrically determining an oxygenation level in biological tissue of a human subject, comprising the steps of:

• selectively providing a plurality of laser light output signals each at a predetermined wavelength of light;
• providing the laser light output signals to an optical fiber, where the laser light output signals propagate through the optical fiber;
• stabilizing the laser light output signals within the optical fiber by redistributing modes of the laser light output signals until an equilibrium mode distribution is established in the laser light output signals propagating within the optical fiber;
• emitting the laser light output signals into the biological tissue of the human subject;
• sensing for the laser light output signals after they have passed through the biological tissue of the human subject, and producing detected signals corresponding to sensed laser light output signals;
• and
• determining the oxygenation level in the region of biological tissue of the human subject using the detected signals and a processor adapted to process the detected signals to determine the oxygenation level.